Morning cortisol levels and glucose metabolism parameters in moderate and severe obstructive sleep apnea patients

Abstract

Obstructive sleep apnea (OSA) has been associated with dysregulation of the hypothalamic-pituitary-adrenal axis and alterations in glucose metabolism with increased risk for type 2 diabetes. The aim of the current study was to compare morning plasma cortisol levels and glucose metabolism parameters between moderate (apnea-hypopnea index (AHI): 15-30 events/h) and severe OSA patients (AHI >30 events/h), with respective controls. A total of 56 male OSA patients, 24 moderate (AHI = 21.1 ± 5.3) and 32 severe (AHI = 49.7 ± 18.1), underwent a full-night polysomnography, oral glucose tolerance test (OGTT), and measurement of morning plasma cortisol levels. These groups were compared to 20 matched subjects in a control group. Morning plasma cortisol levels were statistically lower in severe OSA group than in moderate OSA and control groups (303.7 ± 93.5 vs. 423.9 ± 145.1 vs. 417.5 ± 99.8 pmol/L, P < 0.001). Significant negative correlations were found between morning plasma cortisol levels and AHI (r = -0.444, P = 0.002), as well as oxygen desaturation index (r = -0.381, P = 0.011). Fasting plasma glucose (5.0 ± 0.5 vs. 5.4 ± 0.7 vs. 4.9 ± 0.6 mmol/L, P = 0.009) was higher in the severe OSA group compared to moderate OSA and controls. Homeostasis model assessment insulin resistance (HOMA-IR) was higher in the severe OSA group compared to moderate OSA and controls (4.6 ± 3.7 vs. 2.7 ± 2.0 and 2.2 ± 1.8, respectively, P = 0.006). In conclusion, our study showed that morning plasma cortisol levels measured at 8 a.m. were significantly lower in severe OSA patients than those in moderate OSA group and controls. Morning plasma cortisol levels showed a negative correlation with AHI and oxygen desaturation index. Additionally, this study confirmed the evidence of glucose metabolism impairment in moderate and severe OSA patients, with more pronounced effect in the severe OSA patients group.

The Bidirectional Relationship Between Obstructive Sleep Apnea and Metabolic Disease

“…The involvement of the circadian biology with OSA and sleep disordered breathing also shows great promise ( 183 ). OSA individuals exhibit a circadian dysregulation of cortisol ( 184 ), and treatment with melatonin has been found to mitigate IH-induced hyperglycemia ( 185 ), insulin resistance, and microvascular damage ( 186 ). Research in these fields are on-going and may revel exciting new information about OSA etiology.…”

Epidemiological and pathophysiological evidence supporting links between obstructive sleep apnoea and Type 2 diabetes mellitus

“…Nocturnal hypercortisolism accompanied by low morning cortisol level was found in severe OSA subjects, who had higher insulin resistance when compared to controls. (28) Systemic inflammation, surrogated by high-sensitivity C-reactive protein, fibrinogen, uric acid, and oxidative stress by the expression of inflammatory cytokines, were found to be high in studies of subjects with OSA. (29,30) Vgontzas et al postulated that the proliferation of tumour necrosis factor-alpha in the pro-inflammatory state of OSA suppresses the synthesis of the antidiabetic hormone, adiponectin, resulting in a predisposition to develop T2DM.…”

Health-related quality of life in type 2 diabetes mellitus patients with different risk for obstructive sleep apnea

“…Except cardiovascular and cerebrovascular disorders, metabolic dysfunction is a well-known complication of OSA. 4 , 5 Previous studies have showed increased prevalence and incidence of T2DM in OSA patients compared to general population. 6 , 7 Notably, in a large multiethnic study, prevalence of T2DM increased with worsening OSA severity.…”